Beam optics of the VIISta 3000 ion implanter

An analysis and summary of the beam optics of the VIISta 3000 implanter are presented. OPTICIAN results show the envelope of the ion beam as it progresses from the source, all the way through the implanter to the serial end station. A more in-depth analysis is performed on the portion of the beamline which is located after the high-energy quadrupole lens. That part of the beamline includes the 16.1° charge-selector (filter) magnet, the electrostatic scanner, the 53.9° (corrector) magnet, and finally the 300 mm wafer in the serial end station. The in-depth analysis begins with the determination of the beam envelope throughout the beamline. Next, the fields within the beamline components are calculated. The magnetic field in the filter magnet is obtained using finite-element analysis (FEA). Likewise, the electrostatic field in the scanner and the magnetic field in the corrector magnet are determined using FEA. Contour plots of the fields are presented, Using the FEA results, the ion trajectories are then traced through the fields. Ray-tracing is performed for ions of P⁺ , P⁺⁺, and P⁺⁺⁺. Energy ranges from 10 keV to 3 MeV are examined. The path data is used to quantify the purity of the selected charge states. This data also yields the horizontal and vertical uniformity of the ion tracks where they strike the wafer